In the twelfth-century manuscript as translated by T.H. White as The Bestiary, I note, "Procreation and virginity are common to all, and so is birth, which is not shared among them with any sexual intercourse nor troubled with any unlawful desire, nor are they harrassed with the griefs of childbirth."

It is earlier related, "Many people have proved that these creatures are born from the corpses of cows. The flesh of dead calves is beaten in order to bring them forth, so that out of the rotting blood maggots may be created which finally turn into bees."

How the matter of each of the two passages relates to the other is unclear (to me, at least!).

If there was advance - or even alteration - of apiology between the twelfth-century Bestiary and the fifteenth-century Missal, is more than I know.